Neurological conditions affect a large segment of the human population. With the percentage of people entering their elder years expected to increase in the next several decades, the percentage of people afflicted with a neurological condition is undoubtedly expected to increase as well.
One of the most prevalent neurological conditions is stroke, the leading cause of disability worldwide. Beyond the rehabilitation therapy following a stroke, once recovery from the stroke has reached a plateau and the neurological deficits are fixed, there are no accepted treatments to improve the neurological deficits.
Stem cells, such as neural stem cells, are normally identified, characterized and separated from other cells by immunohistological techniques, such as antibodies, targeting distinct biomolecular targets. However, these techniques are fraught with limitations—most markers as of today are not specific and selective enough to detect and identify neural stem cells in a complex biological system. Further, most existing markers require secondary methods for detection, which is time-consuming. It is also possible to mark selected cells genetically with, for example, a fluorescent protein such as GFP, but such marking requires genetic or invasive techniques and thus a modulation and most plausibly a selection of the cells.
Accordingly, the specific cells, e.g. the neural stem cells, are identified by several markers. Normally, an array, of suitable markers detectable by specific antibodies is used where some are more selective than others for the specific cell type analyzed. However it is the combined use of several markers that detects and identifies the cell type, e.g. the neural stem cell. Thus, each cell type, such as a neural stem cell, has a certain combination of markers on their surface that makes them distinguishable from other types of cells.
It is, however, time consuming and inefficient, and also less accurate, to use an array of less specific markers to detect and identify specific cell types such as neural stem cells. It is also difficult to use an array of antibodies for specific selection and isolation of neural cells, or, alternatively, use a purification method based on several sequential isolation steps using one marker each step. The latter may further prolong the isolation process causing a decrease in viability and quality of the isolated cells.
Thus, the development of molecules for selective and specific identification of single target molecules highly specific for neural stem cells is needed.
Molecules in which two or more thiophene rings linked together are named oligothiophenes. Such compounds possess interesting optical and electronic properties. Examples are fluorescence, semiconductance and light emission if correctly stimulated. One of the most outstanding properties of oligothiophenes is their fluorescence. By changing the structure it is possible to obtain emissions in the full visible spectrum.
Åslund et al reports a novel class of chemically defined oligothiophene derivate for the detection of pathogenic protein aggregates (Åslund et al., ACS Chem. Biol. 2009, 4, 673-684).
There is thus an urgent need to find more selective and specific markers for stem cells, particularly neural stem cells to detect and identify said cells, and to enable selective and specific isolation of said cells using a single target molecule instead of an array to improve viability and quality of the isolated cells. Accordingly, the present invention seeks to provide means and methods to allow such selective and specific detection, identification and isolation of neural stem cells.